In typical systems, a partition within a virtual disk can start at an offset that is not a multiple of the block size used by the physical underlying storage subsystem that stores the virtual disk. As a result, inefficiencies are created in accessing data stored on the storage subsystem. For example, a single block access at the virtualization level (e.g., the access is made to a virtual disk block of a virtual disk partition) may map to multiple physical blocks or straddle multiple physical blocks (e.g., instead of a single physical block) at the underlying storage subsystem. Accessing multiple physical blocks may require reading more data than is needed and discarding the unneeded data, which could be undesirable.